<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h2>逻辑运算符</h2>
    
</body>
<script>
    // let a=-10;
    // let str
    // console.log(!a)
    // console.log(!str)

  //  let str1=''
   // console.log(str1 && 666)
    // console.log(10 && 'abc')
    // console.log(0 && 'abc')
    // console.log(null && 'abc')

    // console.log(10 || 'abc')
    //  console.log(0 || 'abc')
    // console.log(null && 0)
    //let a=10;
   // console.log(a || !(a>10) || a-10)


</script>
</html>